Glossary

Commissioning (Cx)

Also known as: Building Commissioning, Cx

Commissioning is the systematic process of testing, verifying, and documenting that a building's mechanical, electrical, plumbing, and life-safety systems are installed and functioning according to design intent and the owner's project requirements before turnover.

Commissioning is typically performed by an independent commissioning agent working alongside, but separate from, the design and construction teams, and covers systems such as HVAC and building automation controls, fire and life-safety equipment, elevators, and building envelope performance. It is distinct from code inspection: a building inspector confirms code-minimum compliance, while commissioning verifies that systems actually perform as the design intended under real operating conditions, which is a materially higher bar. Commissioning has become a prerequisite for LEED and other green building certifications and is considered essential—rather than optional—on performance-critical asset types such as data centers, laboratories, and hospitals, where a functional deficiency discovered after tenant occupancy can be extraordinarily costly to remediate.